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North Korean soldiers sit on the side of a road in south of Kaesong, North Korea near the demilitarized zone which separates the two Koreas on Wednesday, April 24, 2013. For weeks, North Korea has threatened to attack the U.S. and South Korea for holding joint military drills and for supporting U.N. sanctions. Washington and Seoul said they've seen no evidence that Pyongyang is actually preparing for a major conflict, though South Korean defense officials said the North appears prepared to test-fire a medium-range missile. (AP Photo/David Guttenfelder)

North Korean soldiers sit on the side of a road in south of Kaesong, North Korea near the demilitarized zone which separates the two Koreas on Wednesday, April 24, 2013. For weeks, North Korea has threatened to attack the U.S. and South Korea for holding joint military drills and for supporting U.N. sanctions. Washington and Seoul said they've seen no evidence that Pyongyang is actually preparing for a major conflict, though South Korean defense officials said the North appears prepared to test-fire a medium-range missile. (AP Photo/David Guttenfelder)